1. Field of the Invention
The present invention relates to waterproof construction of communication equipment which is settled outdoors, in particular, to waterproof construction in which a waterproof packing is provided at an opening of a body of the communication equipment, between a lid or a door which blocks the opening and the equipment body, for sealing joints of them.
2. Description of the Related Art
Conventionally, a body of radio communication equipment settled outdoors such as a movable body communication base station is provided with waterproof construction (here, all the construction of waterproof, drip-proof and splash-proof is called waterproof construction in general) at its opening in order to protect electronic parts and electronic circuits on a printed board mounted inside against submergence. Namely, in the waterproof construction of the communication equipment, a groove 23 is provided to one side (or both sides) of joints of an equipment body 21 and a cover (a lid or a door) 22, and an elastic waterproof packing 24 is fit into the groove 23 as shown in FIG. 1. On the occasion of combining the equipment body 21 and the cover 22, the waterproof packing 24 is screwed up by a screw 25 etc. and deformed by the pressure so that the waterproof packing 24 sticks fast to the joint with the elasticity, for perfectly sealing a joint gap between the equipment body 21 and the cover 22. Thus the waterproof packing 24 prevents water from leaking in by its contact pressure.
In such construction that a waterproof packing is held between an equipment body and a cover, the equipment body and the cover need to be screwed up tightly in order that the waterproof packing is pressurized and deformed to have enough contact pressure for preventing water leakage.
However, since compressing the waterproof packing 24 is a necessary factor of the waterproof construction, when, for example, the screw 25 is loose, there is a foreign substance stuck in the joints between the equipment body 21 and the cover 22, or the waterproof packing 24 is partly off the groove 23, the waterproof packing 24 may not bring its intended resilience into full play, and therefore, may not keep prescribed necessary contact pressure.
In this situation, a crevice is generated between the equipment body 21 and the cover 22 as shown in FIG. 2, letting water leak inside the body, and consequently, causing trouble that damages electronic parts and electronic circuits mounted inside. In addition, as shown in FIG. 3, according to the construction where the string-type waterproof packing 24 is set along a periphery of an opening of the equipment body 21, there is a risk of leakage from a joint 27.
Therefore, reliable waterproof construction, which is worked out for protecting the electronic parts and electronic circuits on the printed board mounted inside of the body against submergence even when the water packing does not work efficiently due to an unexpected accident and a crevice is generated between the equipment body and the cover, is desired.
It is therefore an object of the present invention to provide waterproof construction of communication equipment improved to prevent even a little water from leaking in to electronic parts and electronic circuits through the part of a waterproof packing.
In accordance with the present invention, there is provided waterproof construction of communication equipment comprising a waterproof packing at an opening of a body of the communication equipment, between a lid or a door which blocks the opening and the equipment body, for sealing the joint of them, and a water absorber having greater elastic contractibility than that of the waterproof packing, placed on more inside of the equipment body than a position of the waterproof packing, held between the lid or the door and the equipment body.
In this case, it is preferred that the waterproof packing and the water absorber are disposed on facing surfaces of the lid or the door and the equipment body linearly at predetermined intervals so as to surround the opening, and on the occasion of blocking the opening, the water absorber is held between the facing surfaces of the lid or the door and the equipment body before the waterproof packing is held between them. Also it is preferred that the waterproof packing is held in a state of performing required elastic deformation in the process of elastic deformation due to a blockade of the lid or the door and the equipment body.
According to another aspect of the present invention, it is effective that grooves for regulating the position of the waterproof packing and the water absorber are set at least to the lid or the door, or the equipment body on the joints, and that the water absorber is constituted of material having greater elastic contractibility than that of the waterproof packing.
Furthermore, according to another aspect of the present invention, it is preferable that sectional area of the groove is set corresponding to that of the water absorber so that when the elastic deformation of the water absorber takes place in the groove according to the blockade of the lid or the door and the equipment body, the water absorber fills the groove, and swells out to a crevice between the both. Also it is preferable that the water absorber includes a waterproofing film for preventing water from leaking inside of the equipment body in a blocked condition, and the water absorber is previously fitted to a supporting frame in a prescribed shape and held between the lid or the door and the equipment body with the frame, and particularly, the supporting frame is provided to the groove formed on the lid or the door, or the equipment body on the side opposite to the groove housing the water absorber.